found this out not long ago, a nice place to visit.
"In the upper reaches of the Geyser River at the foot of the Kikhpinych Volcano, there is a small valley measuring two kilometers by 100500 meters where animals regularly perish. Special investigations have shown that the death of animals and birds is due to the high concentration of poisonous gases, mainly hydrogen sulfide, carbon dioxide, carbon disulphide, and others. From 1975 to 1983, the reserve carried out regular observations of the valley, and volcanologists analyzed its gas contents. In this time period, over 200 carcasses of animals and birds were collected. Most of the animals that perished were small rodents, passerines, however, specimens also included bears, foxes, wolverines, and among birds ravens and Stellers sea eagles. Since then, golden eagles and lynx have been added to this list. One dog belonging to a reserve ranger also died here. The process is like an ecological domino effect: the first victims are small birds, attracted to thawed patches of snow in the spring; then the foxes come to eat the birds; and after that wolverines and bears, as well as ravens and golden eagles, arrive. When the carcasses are removed, the chain is broken, and the number of victims decreases. Death Valley is situated upwind of deep gas jets. Herbivores (e.g., ground squirrels, hares, pikas, ptarmigans) die less often, and for understandable reasons the slopes and river bottom, which are bare of vegetation, hold no attraction for them. It is phenomenal that the carcasses are preserved for so long without decaying. This is because the poisonous atmosphere of the valley suppresses oxidizing activity of bacteria.Natural phenomena like Death Valley are known on other parts of the planet where volcanic activity is found: Yellowstone Natural Park in the USA (Death Canyon), and on the island of Java in Indonesia, where there are several death valleys. There is another dangerous place in a limestone mine close to Naples in Italy (Grotta del Cane). Everywhere the reason for tragedy is carbon dioxide accumulating in low-lying air layers. Elsewhere in Russia, periodic wildlife deaths (primarily auks) are known on Ushishir Island (in the Kuril Island chain) as a result of fumaroles. In Kronotsky Reserve, there are also powerful upwellings of hydrogen sulfide near the summit of Kizimen and Komarov volcanoes. The Uzon Caldera can be a rather dangerous place near Fumarole Lake where, in addition to hydrogen sulfide, areas with high-levels of mercury are found. The contents of the poisonous cocktail in Kamchatkas Death Valley, however, are much more complex, aggressive, and dangerous than those of other death valleys, and it is unlike any other in the world."
plus, its got space lazers in it that shoot down alien spacecraft that we think are meteors ! You don't know the truth !
well, you'll have to manage with what you got from me last year - my best wishes. 
